Prefabricated water tank

ABSTRACT

A lightweight water tank construction having sidewalls and a grid base, the grid base being formed of a plurality of connecting plates, channel members and capping members designed so as to allow the bottom structure to relatively shift to absorb forces created by ground swelling or water pressure.

United States Patent [56] References Cited UNITED STATES PATENTS [72] Inventor ChozaburoUeno 876 Zimmeman,................. 880 Hendrick....

S T N E T A P N m E R O F 640,580 5/l962 Italy Primary Examiner-Alfred C. Perham Attorney-Fidelman, Wolffe & Leitner The portion of the term of the patent subsequent to Mar. 17, 1987, has been disclaimed.

[54] lfi TANK ABSTRACT: A lightweight water tank construction having r sidewalls and a grid base, the grid base being formed ofa plu- [52] US. 52/265, rality of connecting plates, channel members and capping members designed so as to allow the bottom structure to relatively shift to absorb forces created by ground swelling or water pressure.

3 1 m 5/ 7 2 5 9 00 BE 2" 5 0 7 4 2 5 6 H 2 5 L C 1 n l 5 Field of PREFABRICATED WATER TANK This application is a continuation-in-part of copending application Ser. No. 697,773, filed Jan. 15, 1968 now US. Pat. No. 3,500,602.

BACKGROUND OF THE INVENTION The present invention relates to prefabricated water tanks which can be easily constructed by the mere assembly of the component members.

Water tanks such as water reservoirs and swimming pools are subjected to considerable amount of stress such as water pressure and earth pressure which are applied to the tank structures externally. Therefore, the water tanks of this kind require a structure which can sufficiently cope with these external forces or stresses applied thereto.

Many of the water tanks of the prior art have been constructed by the use of concrete as the principal component material. These concrete structures were built in the following manner. After the foundation work has been completed, iron bars are inserted or erected on the foundation work. Then, these iron bars were enclosed in temporary wooden frames and concrete is poured into these frames containing reinforcement iron bars. This operation is commonly called concrete placing. After the placed concrete has set thoroughly, the wooden frames are removed. Then, the surfaces of the resulting concrete structure are given a waterproof treatment by the application of a plastering. Thereafter, accessory fittings are attached to the resulting structure. The construction is completed with the laying of earth on the ground around the external peripheral walls of the structure. Accordingly, the construction work of this type contained a number of operations which were of the nature that had to be carried out at the site of construction. Therefore, the construction work involved complicated operations such as welding the joints to form aligned surfaces of the structure, and besides, the field operations were such that it was difficult to expect precision work with respect to dimensions or the like. Further, such construction work required, as a matter of fact, a series of procedures which should be carried out in the predetermined order. Moreover, the setting of concrete required a considerable length of time. Thus, the water tanks which were constructed according to the construction method of the prior art necessitated the consumption of a considerable length of period owing to these reasons stated above. In addition, the water tanks having the aforesaid structures of the prior art were of a weight which was of a great magnitude.

In order to improve these disadvantages and drawbacks of the method of construction of the prior art, prefabricated structures utilizing steel component members have been proposed recently. These steel structures, however, are constructed by the use of shape steel bars and ribs of steel plates as the framework members, and steel plates are fixedly attached to these frameworks. In these steel structures also, their construction also involved the work of uniting the component members by welding process, and these operations were mostly carried out at the site of construction. Therefore, such a construction work unexceptionally involved complicated operations which required precision work, but in the same way as has been discussed in connection with the concrete structures, it was also difficult to secure precision in work with respect particularly to dimensions. As a result, the construction of this type necessitated a considerable length of time for the completion of work.

SUMMARY OF THE INVENTION It is, therefore, a primary object of the present invention to improve and simplify the complicated structure of the conventional water tanks such as water reservoirs and swimming pools, and to simplify the conventional complicated method of constructing such water tanks, and also to provide an improved water tank which is light in weight and which can be constructed quickly with a simplified procedure.

Another object of the present invention is to provide a bottom structure which is suitable for use in such an improved water tank and which can be built or fabricated with a simplified procedure.

Other objects, features and attendant advantages of the present invention will become apparent from the following detailed description in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings represent embodiments of the prefabricated water tank according to the present invention, in which:

FIG. 1 is a diagrammatic perspective view of an example of the water tank embodying the present invention;

FIG. 2 is a schematic longitudinal sectional view of the water tank shown in FIG. 1;

FIG. 3 is a diagrammatic plan view, showing the outline of the layout of the bottom structure;

FIG. 4 is a diagrammatic perspective view, with parts broken away, of the essential portions of the bottom structure shown in FIG. 1;

FIG. 5 is a schematical vertical sectional view of a part of the bottom structure taken along the line V-V in FIG. 3;

FIG. 6 is a schematical vertical sectional view of a part of the bottom structure taken along the line VI-VI in FIG. 3;

FIG. 7 is a schematical longitudinal sectional view of a modification of the water tank which is also incorporated in the present invention;

FIG. 8 is a schematical longitudinal sectional view of still another modification of the water tank embodying the present invention;

FIG. 9 is a diagrammatic perspective view, partly in exploded fashion, showing the manner in which the respective sidewall unit members are combined together, and also showing the manner in which the bottom members are combined with the sidewall unit members in the example of water tank shown in FIG. I;

FIG. 10 is a diagrammatic sectional elevation, in an enlarged scale as viewed from a certain angle of FIG. 9, showing the manner in which the sidewall unit members are connected together by the connecting members in the example of water tank structure shown in FIG. 1;

FIG. 11 is a diagrammatic sectional view, in an enlarged scale as viewed from a different angle in FIG. 9, showing the manner in which the sidewall unit members are connected together by the connecting members;

FIG. 12 is a diagrammatic perspective view, with parts broken away, of the preferred relationship of the essential portions of an alternate embodiment; and

FIG. 13 is a vertical sectional view of the relationship of the portions of the embodiment shown in FIG. 12.

The prefabricated water tank of the present invention features a unique bottom or base structure which is formed or installed on a sufficiently firm ground or foundation so as to have a desired floor area. This is done by assembling the following members: cap members being constructed with a plate having a sufficient mechanical strength and having four adjacent marginal end portions which are bent at a right angle along the marginal lines so as to extend outwardly and to form an open box shape having four sidewalls having a uniform length of wall extending in the outward direction from the edges of the plate so as to be used as caps; channel members, made of a material having similarly sufficient physical strength, each having longitudinally extending sidewalls which define a channel therebetween, said channel members being used to join the space between the oppositely facing vertical sidewalls of adjacently disposed cap members; connecting members adapted for connecting the end portions of the ad jacently disposed channel members and which are formed on a plate having a square shape in general; and waterproof caulking which is provided in the spaces formed between the adjacent cap members.

The water tank of the present invention is usually constructed on a firm ground or foundation and is insured of mechanical strength sufficient for coping with the pressure of water which is accommodated in the completed water tank. The manner in which the channel members are arranged together with the manner in which the channel members join the cap members and the provision of the waterproof caulking in the spaces defined by the adjacent cap members, greatly facilitates the construction work, with the result that the period of time required for the completion of the construction is markedly reduced and also that the overall weight of the completed structure is greatly lessened as compared with the similar structures of the prior art.

The construction of the portions corresponding to the sidewalls of a water tank may be performed by employing sidewall unit members which are manufactured for the exclusive use of the water tanks fabricated according to the present invention. In case a water tank is constructed by the use of these exclusively made sidewall unit members, the latter are manufactured so as to have the formation of projections on the end edge faces of each unit wall member in a shape such as is shown, by way of example, at 13 in FIGS. I and II. The connection between these unit wall members and the connection between the wall unit members and the bottom of floor plates is affected by fitting these projections into channel members in such a manner as shown in FIGS. and ll. In the space between the adjacent channel members mounted on the oppositely disposed wall unit members and in the space between the channel-mounted end edges of a wall unit member and a floor member, there is provided a waterproof caulking to produce a sealed watertight continued surface.

Referring now to the accompanying drawings, description of an embodiment of the present invention will be made hereunder in further detail.

A water tank may be installed directly on plane 1 of the ground in the manner as shown in FIGS. 2, 7 and 8 in the event that said ground provides a sufficiently firm and reliable base. In the event, however, that this ground is not sufficiently firm for the installation of the water tank, a foundation 2 having a sufficient firmness and reliability is artificially constructed on top of the plane I of the ground. As shown in FIGS. 3, 4, 5 and 6, the installation of a water tank begins with the placing of connecting members 4, which are of a structure as will be later described, on the surface of the ground 1 or the foundation 2. In the present instance, description will be made to a water tank which is installed on a manmade foundation 2, for the convenience of explanation.

Each of said connecting members 4 comprises a square steel plate and four L-shaped angle steels 3 of a uniform size but small in longitudinal length which are fixed to the upper face of said steel plate in such a fashion that these four pieces of angle steel bars 3 are disposed, one at each corner of an imaginary square of a predetermined uniform size drawn on the face of the steel plate, with the external angle or the apex of each angle steel pointing to the center of said imaginary square and with the planes of the facing walls of two angle steels being disposed in parallel relationship to each other and also being in alignment with the planes of the facing walls of the adjacently disposed angle steels as is clearly shown in FIGS. 3 and 4. The connecting members 4 having the foregoing structure are adapted to receive the channel members 6 in such a way that a channel member is received between a pair of angle steels formed on one face of the steel plate of the connecting member 4 and a pair of angle steels formed on the steel plate of an adjacent connecting member 4 in the manner shown in FIGS. 3 and 4. Connecting members 4 which have the aforesaid L-shaped angle steel bars on one side of the steel plates are laid in predetermined spaced crosswise relationship on the face of said foundation 2 in the manner shown in FIGS. 5 and 6.

In order to insure that these steel plates of the connecting members 4 are laid at an even level with each other on the foundation 2 in such a manner that the upper face of one of the connecting members 4 each bearing four angle steels 3 thereon is in alignment with the planes of the upper faces of the adjacent angle steels, an appropriate levelling material 5 such as mortar, asphalt or the like which is used and it is placed under the lower faces of the connecting members. The connecting members 4 which are disposed on a foundation 2 in the aforesaid fashion can support, with the assistance and cooperation of the angle steels 3 formed thereon, the channel members 6 with stability.

After the connecting members 4 have been laid on the foundation 2 at an even level relative to each other, a channel member 6 is placed so as to straddle over two of the adjacent connecting members 4, with the open channel facing upwardly, said two connecting members 4 being disposed at a predetermined space from each other, so that the channel member 6 spans the area, in bridge form, between these two connecting members 4, with the vertical sidewalls of said channel member 6 being engaged between two pairs of angle steels formed on these two adjacent connecting members 4, at the end portions of these sidewalls of the channel member 6. As a consequence, the channel members 6 which are received between a series of angle steels of a plurality of connecting members 4 disposed crosswise on the foundation 2, form a neatly arranged crosswise grid form, with the respective end portions of the sidewalls of the channel members being engagingly received between pairs of the angle steel bars 3 of the adjacent connecting members. As shown in FIGS. 5 and 6, the spaces 7 which are in the form of meshes and which are defined by the sidewalls of the respective channel members 6, and the spaces 8 which are produced locally beneath the bottom walls of the channel members 6 where the bottom walls thereof are not in contact with the steel plates of the connect ing members or in other words where the channel members span between the adjacent steel plates, are filled with mortar, soil concrete, asphalt or any other appropriate filling material. This filler serves to arrest any reduction in the mechanical strength of the resulting bottom structure of the water tank due to the formed spaces 7 and 8, and also to produce a waterproof continuous surface of the structure.

A cap member 9 is formed by bending the four marginal edge portions of a square steel plate downwardly at right angles relative to the plane of the steel plate to form vertical sidewalls of a uniform length and to thereby form a box having open top, is placed, with the bottom wall facing upwardly, onto the gridlike channel members 6 which are laid on the connecting members 4 in such a way that the four inner peripheral faces of the sidewalls 10 of each cap member 9 are in tight engagement with the inner sidewalls of the channel members 6 which jointly form a mesh which is defined thereby. After the cap member 9 is mounted onto the channel members 6, the mesh which is defined by the sidewalls of the four channel members which are disposed to form a square is closed or covered. Thereafter, the grooves shown at a of the channel members 6 are filled with a water-insulating filling material (which is referred to as I! in FIG. 11) such, for example, as asphalt, to thereby form a watertight bottom structure.

Referring to FIG. 12, the preferred embodiment of the cap member is shown as 20. Cap member 20 has sidewalls 21 and is of a size so that inner peripheral faces of the sidewalls 21 are spaced from the inner sidewalls 24 of the channel members 23. The channel members 23 are in engagement with rightangle members 25 and connecting members 22. Since cap member 20 is larger dimensionally than the area described by the inner sidewalls 24 of four channel members 23, a space 26 is formed between said inner sidewalls 24 and the peripheral faces 27 of sidewalls 21. This is shown more clearly in FlG. 13 with reference being made to the appropriate numerals. The space between the outer faces of walls 21 and the bottom surface of channel members 23 is filled with an insulating material 28 such as asphalt, caulking compound, or the like. The composition is moldable in any case.

This arrangement, i.e., the providing of spaces 26, permits the cap members to be adjustably moved in the channel members depending on the change in water pressure or earth pressure. The fluidity or viscosity of the caulking material permits such movement of the cap members.

Thus, it is seen how this embodiment allows the cap membets to slide sideways with respect to the bottom surface of the channel members enabling the structure to absorb external forces such as water pressure or pressure caused by earth swelling. Such movement does not cause any deformation or buckling of the members. This is important in preventing loss of water from the tank.

In the accompanying drawings, there are shown cap members 9 which are of a boxlike configuration and which are square in their plan view. It should be understood that the shape or configuration of the cap members 9 is not limited thereto which is given only by way of example, and that any desired shape may be adopted as required.

The wall structure which is to be erected so as to surround the peripheral end edges of the formed bottom structure of the water tank may be built according to the method of the prior art.

As a modified embodiment, a gently sloped embankment 12 as shown in FIG. 7 may be constructed first, and after a sufficiently firm and reliable foundation is formed on the ground surrounded by the embankment 12, a bottom structure is formed thereon, and the walls surrounding the bottom structure are formed in exactly the same fashion as that in which the bottom structure has been fabricated as described above. It is also possible to construct the bottom structure so that it has a concave surface as is shown in FIG. 8.

Description will be next directed to an instance where the sidewalls of a water tank are formed by the use of the prefabricated individual sidewall unit members. FIGS. 1, 2, 9 and 11 show one example of such instance. In these drawings, the sidewall unit members 13 are formed so as to have an inverted T-shape by the frame members. Instead of the inverted Tshape fabrication, an L-shape wall structure is frequently used. In any of these fabrications, the walls are formed with the portions which constitute the wall faces and also with the base members which are adapted to fixedly hold the wall portions. The portions of the walls which correspond to the inner faces of the water tank consist of steel plates or iron boards which constitute the main components of the wall unit members.

The connection between the sidewall unit members is accomplished in such a way that L-shaped angle steels 15 are applied onto the rear sides of the adjacently disposed wall unit members as at 14 and 14, respectively, and in the space between the opposing L-shaped steel bars 15, a waterproof filling material 16 is inserted such as asphalt and the resulting sandwich structure consisting of the oppositely disposed L- shaped steel bars 15 and the filler interposed therebetween is nipped between the sidewalls defining the groove of a U- shaped joiner 17. This U-shaped member 17 is further fastened and fixed by means of a fastening member such as a bolt and nut. Thus, a watertight connection of the wall unit members is obtained.

Also, the connection between a sidewall unit member 13 and the bottom member is accomplished as shown in FIGS. 9-11 wherein a channel member 6' having the previously described structure is attached, with the open groove facing upwardly, to the end edge face of the lower portion of the sidewall unit member 13. This channel member 6 is utilized as a part of the groove 0 of the aforesaid grid form. In the manner as has been described, a cap member 9 is mounted thereon by the use of the sidewall 10 of said cap member, and then a waterproof filling material 11 is inserted into the open space defined by the walls of the channel members which are disposed in neat grid form. As a result, a watertightjoint is obtained.

Needless to say the sidewall unit members 13 and the aforesaid members adapted to connect these wall unit members require no uniting or joining operations which are performed at the site of construction.

Of course, the bottom structure shown in FIGS. 12 and 13 can be used in conjunction with sidewall unit members 13 and is actually preferred. The method of connection is the same in both cases.

After the bottom structure and the sidewalls of a water tank have been constructed in the manner described, the remaining operation consists of laying earth around the external walls of the fabricated water tank to form an embankment 20 and also installing a continuous barrier consisting of precast concrete blocks 21. The barrier surrounds the external end portions of the water tank to block the water from getting access to the walls of the tank.

As has been described, the water tank of the present invention is fabricated in watertight fashion by assembling together cap members, channel members and connecting members adapted for fixedly uniting said channel members, and by applying a waterproof caulking in the spaces formed between the joints and channels. In constructing a water tank according to the technique of the present invention, the construction work consists of a very simple assembling operation with the exception of the foundation or groundwork. As such, the operations which are performed at the site of construction are extremely simplified and, as the natural result, the construction work is carried out with a remarkable efficiency and great speed. Also, the individual component members can be produced in large numbers and besides, they can be transported or carried along with great easiness. As a result, these component mem bers can be available at cheap cost. Furthermore, local repair and modification of the construction are made feasible from the use of these component members. In addition, the completed water tank is of a much reduced weight as compared with the similar construction.

In case the water tank is installed on a ground or foundation which is of a considerable firmness and reliability, the completed water tank will, even when it is ofa large scale, perfectly cope with the earth pressure as well as the water pressure which will be applied to the water tank. Another advantage of the present invention lies in that a water tank of a small scale which is of the type for use in the household can be easily fabricated by a nonengineer layman.

It is to be understood that the invention shown and described is not limited to the foregoing and it is to be further understood that modifications and changes may be made without departing from the scope of the appended claims.

What is claimed is:

1. A prefabricated water tank construction comprising a bottom framework consisting of a plurality of capping members, each having a top surface and downwardly extending flanges around the peripheral edges thereof and substantially perpendicular thereto, a plurality of plate members each having a plurality of cornering means mounted on the top surface thereof, a plurality of channel members with substantially perpendicular sidewalls extending between the plates with the channel end portions nesting between two of said cornering means, said capping members fitting over one sidewall of at least two of said channel members and at least one of said cornering means, said capping member flanges being spaced from said channel sidewalls on each side of said channel members, the flange width of said capping members being substantially equal to the height of said channel member sidewalls and the height of said cornering means thereby insuring a substantially rigid and watertight engagement, the areas formed by the outside facing surfaces of said flanges and the bottom of said channel members being filled with a moldable waterproof composition, and sidewalls surrounding said bottom framework, whereby the unfilled spaces between the capping member flanges and the channel sidewalls allow the structure to absorb movement caused by external ground swelling or water pressure.

2. The construction as in claim I wherein said cornering means comprise right-angle members, the planes of the facing walls of any two of said members being parallel to each other and also in alignment with the planes of the facing walls of the adjacently disposed angle members. 

1. A prefabricated water tank construction comprising a bottom framework consisting of a plurality of capping members, each having a top surface and downwardly extending flanges around the peripheral edges thereof and substantially perpendicular thereto, a plurality of plate members each having a plurality of cornering means mounted on the top surface thereof, a plurality of channel members with substantially perpendicular sidewalls extending between the plates with the channel end portions nesting between two of said cornering means, said capping members fitting over one sidewall of at least two of said channel members and at least one of said cornering means, said capping member flanges being spaced from said channel sidewalls on each side of said channel members, the flange width of said capping members being substantially equal to the height of said channel member sidewalls and the height of said cornering means thereby insuring a substantially rigid and watertight engagement, the areas formed by the outside facing surfaces of said flanges and the bottom of said channel members being filled with a moldable waterproof composition, and sidewalls surrounding said bottom framework, whereby the unfilled spaces between the capping member flanges and the channel sidewalls allow the structure to absorb movement caused by external ground swelling or water pressure.
 2. The construction as in claim 1 wherein said cornering means comprise right-angle members, the planes of the facing walls of any two of said members being parallel to each other and also in alignment with the planes of the facing walls of the adjacently disposed angle members. 